package org.example.blog.utils;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.JwtParser;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.io.Decoders;
import io.jsonwebtoken.security.Keys;

import java.security.Key;
import lombok.extern.slf4j.Slf4j;
import org.example.blog.constants.Constants;

import java.util.Date;
import java.util.Map;
@Slf4j
public class JwtUtils {
    //过期毫秒时长
    private static final long JWT_EXPIRATION = 60 * 60 *1000;
    //密钥
    private static final String secretStr = "Le++o8NQWVXWo3+SJtAtnjBW9iA0OvPL0c0mMrol2fU=";
    //生成安全密钥
    private static final Key key = Keys.hmacShaKeyFor(Decoders.BASE64.decode(secretStr));

    /*
    * 生成token
    * */
    public static String genJwtToken(Map<String, Object> claim) {
        String token = Jwts.builder().setClaims(claim)
                .setExpiration(new Date(System.currentTimeMillis()+JWT_EXPIRATION))
                .signWith(key)
                .compact();
        return token;
    }

    /*
    * 校验token
    * clamis 为null 表示校验失败
    * */
    public static Claims parseToken(String token){
        JwtParser build = Jwts.parserBuilder().setSigningKey(key).build();
        Claims clamis = null;
        try{
            clamis = build.parseClaimsJws(token).getBody();
        }  catch (Exception e){
            log.error("解析token失败:{}",token);
            return null;
        }
        return clamis;
    }

    public static Integer getIdByToken(String token){
        Claims claims = parseToken(token);
        if (claims != null){
            Integer userId = (Integer) claims.get(Constants.TOKEN_ID);
            if (userId>0){
                return userId;
            }
        }
        return null;
    }
}
